Electric-arc device



Dec.) 29, 19-25- R. T. CHEESEMAN ELECTRIC ARC DEVICE Filed March 24, 1921 r1 F 76 m 4 W 3/ ail w /7 2/ /7 c I 23 I'm/enter:

His Attorney.

Patented Dec. 29, 1925.

UNITED STATES PATENT OFFICE.

RALPH '1. CHEESEMAN, F LYNN, MASSACHUSETTS, ASSIGNOB TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

ELECTRIC-ARC DEVICE.

Application filed March ?A, 1921. Serial No. 455,257.

To all whom it may concern:

Be it known that I, RALPH T. CHEESE- MAN, a citizen of the United States, residing at Lynn, in the county of Essex, State of Massachusetts, have invented certain new and useful Improvements in Electric-Arc Devices, of which the following is a specification.

The resent invention relates to electric w are dev1ces in which an arc operates in a gas between electrodes of refractory material which are heated to incande'scence duringoperation but are otherwise substantially unaffected by the arc. My invention particularly relates to the starting of an are between nonconsuming electrodes separated by a fixed gap.

In Patent 1,310,067 issued on July 15,

1919, to Philip K. Devers, is described a 510 lamp having tungsten electrodes between which an arc is operated in mercury Vapor.

Ionized vapor is generated preliminary to starting the arc, by an heater dipping into a pool of mercury, 0r an amalgam. In the Devers device the ionizing circuit is o ened in response to current flow therein'a ter a predetermined time interval has elapsed. n case the arc has not started by that time the ionizer is again connected in circuit and the starting cycle is repeated.

As a result of my present invention, a simplified starting mechanism is provided in which the ionizer remains continuously in circuit until an arc has started and is deenergized in response-to flow of energy in the arc circuit. mong the novel features of my invention is anarrangement for impressing at starting a highvoltage upon the electrodes of each device, independently ofother devices, and automatically reducing this voltage when the arc has started.

The accompanying drawing illustrates an embodiment of my invention as ap lied to the starting of an incandescent arc lamp.

Referring to the drawing, the arc lamp illustrated comprises an elongated envelope 1 into which are sealed conductors 2, 3 tipped by stems 4i, 5, to which are connected electrodes 6, 7, of refractorymetal such, for example, as tungsten. Immediately below the electrode 6, 7, is locateda globule 8 consisting of mercury, or an amalgam. Dippin into the mercury is a wire 9 connected to the stem 5 and tothe' leadin -in conductor 10. Preferably a gaseous filing is'provided in the bulb 1, for example, argon at a pressure of about 20 to c. m. of mercury.

Electric current is supplied by a transformer 12, (in this case an auto-transformer), the primary circuit of which is connected by the conductors 13, 14, to an alternating current supply circuit 15. The auto-transformer is provided with a high voltage winding 16, the free terminal of which is connected by the conductors 17, 18, to the electrode 6, both in series with the magnet winding 19 and with the mercury body in the mercury switch 20, which, when no current is flowing is in contact with the terminals 17, 18'. The electrode 7 is connected by a conductor 21 to a point of intermediate potential on the primary winding 12.

The mercury switch 20 is provided with a third terminal 22 connected by a conductor 23 to a point of intermediate potential of the autotransformer, whereby current from the transformer section between the con ductors 23 and 21 operating as second ary may be conveyed. When the switch 2t is closed, current traverses the ionizer 9, heating the same to incandescence. Mercury is vaporized and ionized by contact with the incandescent wire. Ase high voltage is impressed on the electrodes 6, 7, namely, the voltage between the points of connection on the transformer of the conducto-rs 17 and 21, an arc is readily started between the electrodes 6, 7.

When the arc-sustaining current traverses the coil 19, the core 25 is pulled up tilting .the switch 20, which is pivotally supported at 2B. The mercur runs into the bent arm 27, completing a circuit through a contact 22 to the transformer by the conductor 23 and breaking contact with the terminal 17 As a result the circuit connection of the electrode dis shifted from the high volt- -will continue to operate at low voltage when the electrodes have been heated to incandescence, current being supplied by-' the transformer section between the conductors 17 and 23 which constitutes a low voltage secondary.

When the arc current begins to How and core 25 is pulled upward the double-pole switch 30 in circuit with the conductors 31, 32, connected to the ionizer 9 is opened, thereby deenergizing the heater.

It will be observed that the denergizing of the ionizer and the shifting of the arc from a high voltage to a low voltage is accomplished by a simple movement of a magnet. The described device is suitable for series or multiple circuit operation. For the purpose ofillustration a second set of lamp connections has been indicated connected to the same supply conductors.

What ll claim as new and desire to secure by Letters Patent of the United States, is

1. An electric arc apparatus comprising an electric arc device, circuit connections for delivering current which is capable of starting and operating an are between said electrodes in the presence of ionized vapor, means within said lamp for furnishing ionized vapor to the space between said electrodes, an electric circuit for supplying said device with current at lower potential, and

means responsive to flow of current between said electrodes for transferring the connec tions of said device to said lower potential. circuit, said means being adapted to break the circuit of higher potential after the circuit of lower potential has been established. 2. An electric arc apparatus comprisin an arc device containing electrodes adapts to operate at incandescence, separate means therein for furnishing ionized vapor to the space between said electrodes, at source of current havin both low potential and high potential win ings, connections to said electrodes from the high potential winding, a connection between the low potential winding and said ionizing means, and electromagnetic means responsive to current flow between said. electrodes for disconnecting said ionizing means and shifting connections to said electrodes from the high potential I to the low potential winding.

3. An electric are system com rising the combination of a gas-filled arc evice having refractory electrodes separated by a fixed gap, a transformer having a high potential winding and a low otential winding, said windings being initially connected in series to said electrodes, means for. start-= ing a discharge between said electrodes, and

means responsive to flow of current between said electrodes for changing connections to supply said electrodes exclusively by said low potential winding.

4; An electric are system comprising the combination of an arc device havi clos trodes separated by a fixed gap and a opted to vi'apersute at incandescence, a transthinnermemes connected to supply said electrodes with current, means for starting an are between said electrodes, and electroma netic means responsive to flow of current etween said electrodes to both deenergize said starting circuit and to materially lower the potential of the current supplied from said transformer. a

5. An electric arc system comprising the J to current flow between said electrodes,

means for initiating an are between said electrodes and a switching means controlled by said magnet for altering current connections to said are device from said supply means to lower the impressed potential when the arc has started and to energize said holding winding whereby the lower potential connection, is maintained.

6. An electric arc apparatus comprising an enclosed arc device having electrodes normall out of contact with each other, means or supplying current at a voltage higher than the normal operating voltage of an are between said electrodes, means for starting an are between said electrodes, a switch for changing connections of said denormal operatin value, a second switch for deenergizing sai starting means, and means responsive to current flow between said electrodes for operating both of said switches.

7. An electric arc apparatus comprising the combination of an arc device having refractory electrodes operating in a gas at substantial pressure, a source of current, circuit connections between the electrodes of said arc'device and said source, means for ionizing the gas filling in said device, and means responsive to current operating an arc in said device for deenergizing said starting means and for rearranging the com nections to said source to lower the voltage applied to said electrodes. v v

8. An are system comprising the combination oi an arc device containing a starting means, a transformer provided with taps for furnishing current at diilerent voltages,

circuit connections between said starting means and low voltage taps of said transafige taps while keeping an are between said 8 ectrodes in operation.

9. An are system adapted for the operadevices having refractory elecan ionizing circuit which comprises the combination of a transformer having low voltage and high voltage windings, circuit connections from the high voltage windings to said electrodes, a mercury switch having contacts whereby the connections from are electrodes may be shifted from a high voltage winding to a low voltage winding, an electroinagnet responsive to arc current for operating said switch and a second switch also operated by said electromagnet for opening said ionizing circuit when said mercury switch is operated.

- 10. An are system which is adapted for tion of arc trodes and the operation of an are between electrodes remaining normally outof contact with each other comprising the combination of a transformer having both a low voltage winding and :a high voltage winding, circuit connections from said windings to said elec trodes, a separate circuit for starting said are, electromagnetic means for opening said starting circuit in response to current in the, arc circuit and a mercury switch operatively connected to said electromagnetic means and having a set of contacts in said high voltage circuit and a set of contacts in said low voltage circuit, the mercury filling in said switch being operative to shift, circuit connections from one set of contacts to another while maintaining the continuity of current supply.

11. An arc system comprising a transformer having a plurality of taps, an ionizing circuit connected to a pair of said taps, an are starting circuit connected to taps of higher potential, a mercury switch having cont-acts which, when bridged, will complete botlrof said circuits, a third circuit connected to taps of low potential on said transformer and including a third terminal in said switch to which'contact is made when the other contacts are opened, an electromagnet responsive to current in the are starting circuit for operating said mercury switch and a cut-out in said ionizing circuit which is opened by the operation of said electromagnet, said mercury switch being constructed to close the third circuit before the are starting circuit is opened.

In witness whereof, I have hereunto set my hand'this 17th day of March, 1921.

RALPH T. CHEESEMAN. 

